Recent reports of the demonstration of the efficacy of pharmacological treatment of mild hypertension have enhanced the importance of developing methodology for less toxic treatment of the millions of individuals with this disease. Weight loss and reduction of sodium intake have been shown to lower blood pressure in some settings. Physical activity can contribute to weight loss and possibly to blood pressure control. Although ideally we would test each factor independently, due to their inter-relationships, modification of one factor often results in changes in others. In the proposed project the efficacy of a multifactorial approach to lifestyle changes in these areas, implemented through behavioral self-management techniques taught in the workplace, in reducing the requirement for blood pressure medications will be tested. It is proposed to carry out the project among the obese hypertensive employees of two large companies primarily composed of office workers. Maximum use will be made of ease of communication with the employee at the worksite through weekly group meetings and individual counseling sessions during a 3 month intensive lifestyle intervention program. The patient will learn 3 basic behavior change processes: self-observations, appropriate setting of intermediate goals (i.e. shaping) and the use of behavioral techniques change such as cues, substitution of incompatible behavior and positive reinforcement. The individual will continue to have less intensive intervention and observation in a maintenance phase of 9 months of monthly contacts, and then be observed without intervention during additional 6 to 12 months. Blood pressure, weight, sodium excretion, drug regimen, side effect history, patient attitudes and beliefs, and exercise patterns will be followed. The primary endpoint will be blood pressure reduction and/or reduction of blood pressure medications. Should this project be successful it is hoped that it would result in the development of program which could be utilized by existing health personnel in occupational settings with minimal outside help.